302 Small-Block Engine Build - A Wolf Among Mice

This Race-Inspired 302 Puts Up Some Mighty Numbers

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302 Small-Block Engine Build - A Wolf Among Mice

The custom Airflow Research 195cc Eliminator cylinder heads were treated to full competition port upgrades and now feature a 60cc combustion chamber (they come out of the box with either 65 or 75cc chambers).

The intake and exhaust ports are works of art, as are the exhaust valves...

...which have been smoothed and rounded for better evacuation of exhaust gasses.

The work done to the AFR heads was performed by Bill Goyett of Precision Specialty Service in Palmdale, California. Bill made plaster casts of the stock '69 cylinder heads and from there mapped the contours of the plaster casts into the CNC computer.

Prior to any CNC machine work, the accessory holes are filled in, then the machine takes over and starts milling away. (For more pictures and info on the process, check our web site, superchevy.com. We have an exclusive web story on the machining.)

The set of cylinder heads on top are the original factory cast iron heads, while the set on the bottom are the AFR heads disguised to look like the OE heads. The differences are so subtle it would be hard to tell them apart at first glance. The pair of cast iron heads weighs 94 lbs, while the pair of AFR heads weighs 59 lbs. Any time you take 35 lbs off the nose of a car it's a good thing.

As mentioned earlier in the story, the original 302 block has been bored .040-over; the cylinder bores measure 4.040. Also, the block has also been decked .025-inch. The current displacement measures in at 333 ci.

The connecting rods that were used are lengthened Oliver 6.250-inch-long parabolic beam with full floater lightweight wrist pins. Compare the length of the Oliver rod with the length of the stock 5.7 rods.

The crank that John chose is a Callies 3.250-inch stroke lightweight crank...

...with Federal Mogul H-series race bearings.

After the stoutly-built bottom end is assembled, John buttons it all up.

The cam that was used is a Comp Cams solid roller. The intake lift is .601-inch and duration of 254 at .050; the exhaust lift is .604-inch with 260 duration with a 110 lobe center. The timing chain used is a Cloyes dial adjust with thrust bearing.

Wherever the fasteners were not visible, ARP bolts were used in the build. In order to keep the period correct look for the engine, owner Clif Warren opted to use reproduction bolts from Classic Industries.

Part of keeping with the visual theme of this engine was to use as many NOS parts as possible. That includes the mint timing cover and, of course, period correct bolts.

The oiling system includes a Melling high volume oil pump with ARP drive.

The block was turned over and top dead center was established. The piston is actually positive .002 above deck height. This maximizes the quench which makes for better combustion in the combustion chamber.

The one thing on the engine that does not have a stock appearance is the Moroso 7-quart oil pan with built-in windage tray. When it comes to the oiling of the engine, functionality is a priority over aesthetics.

Fel-Pro and Cometic gaskets were used throughout the build. The head gaskets seen here are from Cometic.

Now the cylinder heads are bolted on. The custom solid roller springs and titanium retainers have already been installed by AFR.

Now that the all the major components are bolted on, the orange cans of Krylon are rattled and rolled. Now this is a true Chevy Orange engine.

Crower Enduro 1.55 ratio rockers increase the duration and lift of the already large cam.

In order to complete the look, a beautiful set of NOS valve covers was used, but had to be clearanced as well as having some of the edge shaved off. They fit and they look perfect.

Nothing looks meaner in a '69 Z/28 like the original cross-ram intake. While Warren does own a few original intakes, he opted to use an aftermarket re-pop for this build. In order to use the cross-ram with the AFR heads, a fair amount of work had to go into the shaping and port matching of the intake. The ports had to be moved a little up and over for a proper fit--you can see the groove milled down the side of the intake. Without this groove the intake will not fit onto the AFR heads and the valve covers will not fit either.

Here's a closer look at the intake before the lid is bolted on. The runners on the intake were also extensively machined and smoothed for the best possible air and fuel flow.

Carburetion is two 500 CFM Holley double pumpers that are identical to the ones used in 1969.

The linkage setup on these carbs is all mechanical. If you notice in the picture, the primaries are open three quarters of the way before the secondaries open.

With nearly everything bolted on, this is what the Little Wolf looks like. It's a perfect retro looking engine with the best technology that is offered today.